- Coronaviruses are named for their crown-like shape, and were first identified in the mid-1960s. The virus typically causes respiratory illnesses like the common cold.
- A new
studyfound the virus may have originated in bats and then spread to humans via a snake or pangolin.
- Seven coronaviruses are known to infect humans.
All data and statistics are based on publicly available data at the time of publication. Some information may be out of date.
The coronavirus originating in Wuhan, China, is baffling experts searching for the source. Since the virus is considered novel, it’s a type of virus that has never been encountered before.
Coronaviruses are named for their crown-like shape, and were first identified in the mid-1960s. The virus typically causes respiratory illnesses like the common cold.
In the beginning, many of those infected worked or shopped at a wholesale seafood market in Wuhan, China, which also sold live and freshly slaughtered animals.
This is why experts suspect it crossed to humans from an animal host.
According to Chinese state media, researchers at South China Agricultural University have analyzed over 1,000 metagenome samples of wild animals to find pangolins, a type of anteater, are the most likely intermediate host of the novel coronavirus.
“They found that the sequence of the coronavirus strain assembled from metagenomes was 99 percent identical to that of infected people in the recent coronavirus outbreak,” reported state media.
Shen Yongyi, a professor with the university and member of the research team, told the Xinhua news service that although previous research found the novel coronavirus originated in bats, the animals hibernate in winter, making it unlikely that they caused the current outbreak.
However, the actual study hasn’t been published. So far, the university has only issued a press release.
“The evidence for the potential involvement of pangolins in the outbreak has not been published, other than by a university press release,” said Professor James Wood, PhD, Head of Department of Veterinary Medicine, University of Cambridge in a statement. “This is not scientific evidence; investigations into animal reservoirs are extremely important, but results must then be published for international scrutiny to allow proper consideration. Simply reporting detection of viral RNA with sequence similarity of >99 percent is not sufficient.”
According to study authors, the infection could still have been passed to humans through an intermediary animal. A previous study theorized that it went through snakes before being passed on to humans.
“Although our phylogenetic analysis suggests that bats might be the original host of this virus, an animal sold at the seafood market in Wuhan might represent an intermediate host facilitating the emergence of the virus in humans,” wrote the study authors.
Bats have an unfortunate history of passing potentially deadly pathogens to human hosts.
A 2017 article in
“Whenever a species jump appears, whenever a virus jumps from one species to another — that species will not initially have a well-developed immunity to the virus. As time passes our ability to fight the new virus increases,” Dr. Waleed Javaid, Director of Infection Prevention and Control at Mount Sinai in New York, told Healthline.
This isn’t the first time a pathogenic coronavirus has crossed over from an animal host. Ebola, severe acute respiratory syndrome (SARS), and Middle East acute respiratory syndrome (MERS) are recent examples.
“There are many different theories, but what seems to be a consistent approach in our findings in all of them is that there might have been species jump,” Javaid said.
He explained there are seven coronaviruses that infect humans, including the new virus.
“Four of them actually cause common cold and they have been with us for a very long time, maybe a few more will be identified with time, and those are mostly limited to human populations. SARS, and especially MERS, are considered a jump from another species to humans and this new virus is another possible jump.”
A recent report in the New England Journal of Medicine (NEJM) published in January found that “increased preparedness is needed at animal markets and other animal facilities, while the possible source of this emerging virus is being investigated.”
“We already have structures of the virus. I think it should be emphasized how rapidly the scientific and medical community is now geared to respond to these things,” said Dr. Asim Ahmed, a pediatric infectious diseases attending physician at Boston Children’s Hospital and Senior Medical Director, Karius Inc.
Ahmed confirmed that every time we go through an outbreak of this type, there are systems in place from previous occurrences. “So we get structures, we get isolation in a virus; they’re already talking about developing vaccines. A little bit is getting the genetic information, the sequencing will be critical. With the sequencing of different strains, you can assess the population and transmission dynamics of what strain came from where, because the sequence ties the virus to its origin.”
People in China are desperately trying to get their hands on face masks, believing that wearing one will protect them from exposure to droplets sneezed or coughed out by those infected with the Wuhan virus.
“There hasn’t been a general call out for the general public to start wearing masks. Some people may be taking those measures on their own,” said Ahmed.
Ahmed said the Centers for Disease Control and Prevention (CDC) is recommending good hygiene, and telling people to stay home from work if they’re sick. “And if they’re sneezing or coughing to do so appropriately, like coughing into their sleeves instead of into your hand, because if you cough into your hand you can spread that around.”
He emphasized the importance of cleaning hands, and using an alcohol-based hand sanitizer when soap and water aren’t available. Also, to avoid close contact with people who are sick and to routinely disinfect surfaces.
“The other thing is to avoid touching your eyes, or your mouth, because those are areas where you can directly transmit pathogens into your body,” Ahmed said.
How effective is screening after potentially infected people have already mixed with crowds in those areas?
“It’s an imperfect system but, you know, we have to balance — in free liberal countries, there are obviously some trade-offs. Countries that exercise control over their populations have more stringent means to control this sort of thing. You have to balance those interests; people’s health, but also individual liberties and freedoms,” said Ahmed.
He concluded, “It’s tough to predict at this time, but I think that people should exercise some degree of caution and awareness that this could be a big deal, but we don’t know that yet. We have to prepare ourselves in terms of outbreak and epidemic response and the government is obviously gearing those efforts and certainly on a hospital by hospital basis we’re gearing up for those sorts of efforts.”
The new virus first identified in Wuhan, China, is a type known as coronavirus. Like previous outbreaks of SARS and MERS, it probably jumped to humans from an animal. Researchers have found evidence it may have originated in a bat, but then a second animal like a snake or a type of anteater called a pangolin may have transmitted it to humans.
Although the virus can have severe effects on people now, experts say that this can diminish over time as our immune systems adapt.
Efforts to contain the virus aren’t perfect, but they’re the best health officials can implement without infringing excessively on people’s rights.
Experts emphasize that it’s too soon to tell what will happen, but governments and healthcare facilities are gearing up to deal with the emergency.